Method of precipitating metals electrolytically.



UNITED STATES PATENT FFIQE,

ARTHUR RAMEN, OF HELSINGBORG, SWEDEN, ASSIGNOR TO HIJLSINGBORGS KOPPARVERKS AKTIEBOLAG, OF HELSINGBORG, SWEDEN.

METHOD OF PRECIPITATING META-LS ELECTROLYTICALLY.

Specification of Letters Patent.

Patented Feb. 23, 1909.

Application filed August 27, 1906. Serial N 0. 832,249.

To all whom it may concern:

Be it known that I, ARTHUR RAMiiN, a subject of the King of Sweden, and resident of Helsingborg, in the Kingdom of Sweden, have invented certain new and useful Improvements in the Methods of Precipitating Metals Electrolytically, of which the following is a specification.

The hitherto known method of precipitating metals from solutions of metal salts, all have the disadvantage of a very great expenditure of energy being necessary for the precipitation of the metals, due to the difficulty of maintaining a low difference of potential of the anode and the cathode.

In order to make it possible to reduce the expenditure of energy, the difference of po tential, which has hitherto by practical reasons been very high, must be maintained at a low rate, and this is attained by reducing the polarization. For this purpose one has, hitherto, tried to attain this purpose by introducing into the anode chambers depolarizing liquids, generally consisting of lyes or solutions, WlllCll come from the cathode chambers Where they have been deoxidized. In the anode chambers these liquids have a depolarizing action thereby that they are themselves oxidized by the action of the current. However, it has not been possible, according to the said methods, to constantly maintain the difference of potential at a low rate, due to the impossibility of keeping the said depolarizing llquids at a constant composition.

This invention relates to-a method, by means of which the expenditure of energy in electrolytical precipitation of metals'from solutions of the corresponding salts is reduced in a very essential degree. The said method consists in using as a depolarizing agent in the anode chambers a lye obtained in the manner, that a part is separated from the solution, from which the metals are to be precipitated, and from this part the more negative metals are precipitated by means of iron in the usual manner. The lye resulting from the said precipitation of the more negative metals substantially consists of a solution of ferrous salts, and, having been introduced in the anode chambers, acts as a depolarizing medium thereby that the said lye is oxidized when acted upon by the current. The rest of the original solution of metal salts is introduced into the cathode chamber, in which it is subjected to an electrolyzing process, during which the negative metals are first precipitated and then, after the terminal voltage has been increased, the positive ones. The present method may, for instance, be used in the electrolytical precipitation of copper and other metals from the solution obtained at the lixiviation of ores roasted according to the method of chlorinationroasting. The lye obtained at the said lixiviation and from which the metals are to be Won iselectrolyzed in the cathodechambers. As a depolarizing medium in the anode chambers is used the lye, which results after the precipitation by meansof iron of the copper and other negative metals from one part of the solution obtained at the said lixiviation processor from a solution of an analogous composition.

Owing to the fact that the lyes, used as depolarizing mediums, according to my invention are produced outside the electrolytical bath, which hitherto has not been the case, they may be concentrated to any desired degree and have any desired composi tion, and in this way a practical solution is provided of the problem of continuously maintaining the difference of potential of the electrodes at a low rate and thereby,

reducing the expenditure of energy 1n electrolytical precipitation of metals from the solutions of the same.

In methods hitherto used the solutions or lyes, from which the copper, silver, zinc and many other metals are precipitated electrol tically, owing to the fact that the same ye was used both as cathode liquid and as anode liquid and in most cases also as lixiviating medium, were so mixed with other metals, as iron, arsenic etc, that pure metals could not be precipitated from the same and that more positive metals, as zinc, nickel etc. after the more negative metals had been precipitated, could not be utilized for the reason that the purifying of the lyes involved too reat expenses. In using my method on t e other hand, the lyes, from which the metals are to be precipitated electrolytically, are not made impure at all, and, consequently, nearly chemicall pure copper, silver, or other metals can e precipitated from the same and, after the more negative metals previously have been preany waste lye may be used, which results after the precipitating of copper or other metals from a solution which has a compo-- sition analogous to that of the solution from which the metals are to be precipitated electrolytically.

Having now described my invention, what I claim as new and desire to secure by Let ters Patent is:

1. In the electrolytic recovery of metals, the process which comprises electrolyz-in a solution containing readily electrolyza le metals while maintainin a solution of ferrous salts, substantially Iree of such metals, about the anode of the electrolytic cell.

2. In the recovery of metals, the process which com rises reducing a solution contain- .ing reduci le metals by means of metallic iron, electrolyzin a solution containing readily electrolyza le metals and maintaining a body of such reduced solution about the anode during such electrolysis.

3. In the recovery of metals, the process which comprises treating one portion of a solution with metallic iron to reduce readily reducible metals therefrom, electrolyzing another portion of the same solutlon and duranode.

ing electrolysis maintaining a bod of the first reduced portion about the anode.

4. In the recovery of metals, the process which com rises leaching calcined ores, electrolyzing t e leachings obtained and during the electrolysis maintaining a solution of ferrous salts in proximity to the anode.

5. In the recovery of metals, the process which comprises leachin calcinedores, reducing a portion of the eachings with metallic iron, electrol zing the remainder of the leachings and uring electrolysis maintaining a body of the reduced portion in. proximity to the anode.

6. Inthe recovery of metals, the process which comprises leaching calcined ores, reducing a portion of the e liquid, electrolyzing the remainder of the leachings, and during electrolysis maintaining a body of the concentrated reduced portion in proximity to the anode.

7. In the recovery of metals, the process which comprises leachin a calcined copper ore, treating a portion the leachings with metallic iron to precipitate the copper therefrom, and electrolyzing the residue of the leachings and during electrolysis maintaining the treated portion in proximity to the In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

ARTHUR RAMEN. Witnesses:

AXEL NELSON, N. E. HILLER.

achings with me tallic iron and concentrating the reduced 

